XQD uses PCIe Gen 2 x1 for up to 440 MB/s in Nikon D5 and D500 cameras. Largely replaced by CFexpress Type B which is physically compatible.
| Pin | Name | Function | Type |
|---|---|---|---|
| 1 | GND | Ground | GND |
| 2 | TX+ | PCIe TX positive | BUS |
| 3 | TX- | PCIe TX negative | BUS |
| 5 | RX+ | PCIe RX positive | BUS |
| 6 | RX- | PCIe RX negative | BUS |
| 8 | REFCLK+ | Reference clock positive | BUS |
| 9 | REFCLK- | Reference clock negative | BUS |
| 10 | VCC | 3.3V power | PWR |
| 12 | PERST# | PCIe reset | I/O |